The woman, 42, was a passenger in a car that was sideswiped about 9:55 p.m. in the 1200 block of West 92nd Street, Chicago police said.
Both vehicles stopped so the people inside could check the damage, police said. However, when the other vehicle left, someone inside fired shots, striking the woman in the arm.
The woman was taken to Little Company of Mary Hospital in fair condition, police said.
Area Two detectives are investigating.